Neuroscience encompasses a broad range of hypotheses, explorations, technologies, and models; neuroscientists are a diverse group with grounding in many disciplines. The scope and range of neuroscience data is ever more complex, and the number of laboratories acquiring and analyzing data digitally continues to increase. As a result, the need for neuroscientists to be able to exchange data is significant and growing. The project will enhance and expand databases focused on neurophysiology, as well as standards for data exchange and interoperability that span contemporary brain and informational sciences. Three open accessible Web resources will support sharing of neurophysiology data and present techniques for Human Brain Project (HBP) interoperability: neurodatabase.org, brainml.org, and datasharing.net. The five linked Aims of this ongoing project fuse neuroscience and informatics to develop HBP areas of programmatic interest including: "databases, graphical interfaces, querying approaches, information retrieval, data visualization and manipulation, and data integration through the development of integrated analytical tools, synthesis, and tools for electronic collaboration." Aims I and II enhance and expand neurodatabase.org and its user-friendly multiplatform query, viewer, metadata, and data entry tools to aid data exchange and reanalysis for data from additional mammalian brain regions and preparations, and from genetically-altered model systems, linking neuroinformatic with bioinformatic metadata. Towards interoperability, Aims III and IV will enhance and expand BrainML, the extensible standardized data description language designed by the project to serve as an interface among neuroscience databases and between databases and their users. After completing BrainMetaL abstractions and BrainML multilayered language definitions for neurophysiology and cortical data, and demonstrating links to peer resources, the project will integrate project-designed and compatible community-derived extensions supporting a wide range of neurobiological techniques and preparations. The fifth Aim leverages this work to develop, offer and support two resources to enable neuroinformatics developers to provide complementary, interoperable data sharing for other areas of neuroscience. The Neurodatabase Construction Kit will aid other neuroscience communities to more rapidly design and implement neurodatabases. BrainML-X will enable HBP groups to build interfaces, query servers and distributors, and mediators to implement interoperability among neuroinformatic resources